Improvement in core-barrels for casting



W. SMITH.

Core-Barrels for Castings.

N0* 142,746l Patented September9,1873.

v If'wentor.

Witnesses 'ITnD STATES PATENT OFFICEo WILLIAM SMITH, OF PITTSBURG,PENNSYLVANIA.

IMPROVEMENT IN CORE-BARRELS FOR CASTING.

Specification forming part of Letters Patent No. 142,746, datedSeptember 9, 1873; application tiled June 4, 1873.

To all whom it may concern:

A Be it known that I, WILLIAM SMITH, of Pittsburg, in the county ofAllegheny and in the State of Pennsylvania, have invented certain newand useful Improvements in Collapsing Gore-Barrels, used in themanufacture of cast iron pipe, and do hereby declare that the followingis a full, clear, and exact description thereof, reference being had tothe accompanying drawings and to the letters of reference markedthereon, making' a part of this specification.

My invention relates to that class of corebarrels which have for theirobject the relief of the pipe-casting while cooling, and the doing awaywith the use of straw rope for that purpose, as well as the preventingof cracks and flaws in the casting; and the nature of my inventionconsists in the construction and arrangement of an expanding andcontracting corebarrel, used in the manufacture of castiron pipe, thesaid core-barrel to be expanded to a certain size when the core is beingmade, and contracted to a smaller diameter after the metal has beenpoured around it, and while the same is cooling, thus preventing anystrain A or binding of the casting, and allowing a free escape of gasand air.

In order to enable others skilled in the art to which my inventionappertains to make and use the same,I will now proceed to describe itsconstruction and operation, referring to the annexed drawing, in which-Figure l is a longitudinal section of my core -barrel through lines x m,Figs. 2 and 3. Fig. 2 is a cross section through the line y y, Fig. l,and Fig. 3, a similar section through the line z z, same figure. Fig. 4is a section and side view of the outside shell before it is cut intoplates.

A represents the central spindle or shaft to which all the movable partsare affixed. The body of this shaft may be square or round, as desired,and it is provided with trunnions at cach end to allow of its beingrevolved when the core is being made. At regular distances dished piecesor plates B B are securely fast cned to the shaft A by keys orset-screws, which pieces or plates have an angular face to lit tightly,when the barrel is fully expanded, npon sloping projections II Il on theplates which form the outside of the barrel. The dished pieces or platesB B may be made round, square, octagonal, or any other suitable shape,and the projections H H made of corresponding shape. Directly below eachof the pieces or plates B on the shaftAis placed a frame or hub, C.These hubs must not be rigidly attached to the shaft, as I lind inpractice that they must have a certain amount of movement in order toallow the plates B B to leave their seats and get above them before thecollapsing motion commences. This I accomplish by making an oblong slot,a, in two sides of each hub,in which a pin, b, fastened in the shaft A,works. rlhis allows the shaft to move upward a certain distance beforethe contraction begins. These hubs have four sets of lugsfarranged toreceive each one end ot' the movable togglearms E E. Immediately beloweach of the hubs C is another hub, D, of exactly the same shape, andanswering the same purpose. They meet the upper hubs end to end when thebarrel is fully expanded, as shown 5 but when the barrel is contractedthese hubs D D slide loosely on the shaft and drop below. d d arelugs-in which'the outer` a-ngles of the toggles E E are secured.- Thelugs are then bolted to the plates forming the outside of thecore-barrel, and regulated by set-screws. G G represent the outsideplates of the barrel, circular in form, each being the segment of acircle. They are perforated with a number of small holes to hold the mudof the core and admit of the gas escaping, and they are provided at theproper places with the angular seats H EI projecting inward, into whichthe plates or pieces B B fit. I represents the bottom or head plate ofthe barrel, made with an angular face fitting into a seat in the base K,which forms the bowl of the pipe. The bottom'I is made with arms and ahub tting the shaft A, and having a keyhole matching a similar hole inthe shaft. Below this hub a thread is cut upon the shaft, upon which anut, M, works. L is the base plate, on which the bowl-piece K is placed,which also acts as a foundation for the ask. When the barrel isexpanded, open spaces e e are formed between the plates G G, as shown inFigs. 2 and 3, to allow of its contraction. These spaces are of a Vshape, opening outward in order to form ,a base for the mud of the coreto rest in, and offer a resistance to the pressure of the iron.

In lieu of the V shape of the openings I may use a thin sheet-metalplate, f, covering -the opening, and extending the whole length of thebarrel to prevent the melted iron from forcing its way through the mudinto the barrel.

In constructing my core-barrel, I cast the outside plates G G in onepiecethat is to say, in pipe form, as shown in Fig. 4:; and after thetoggle-joints,wedge-plates, and shaft have been fitted therein, I cutthe open spaces e e by means of a planer, thus dividing it into fourparts, and securing uniformity of size and shape in the core-barrel,which is of the utmost importa-nce.

The pieces or plates B B are provided with openings i t', as shown inFigs. l and 3, to allow of the easy escape of gas, &c.

The barrel thus constructed being collapsed, and the workman about toform a new core upon it, the barrel is first placed in its necessaryposition on the horses, the nut M is started on the thread, and as it isscrewed up and advances it forces up the plate I and the loose hubs D D,at the same time drawing the angular faced plates B B into the seats H Huntil the hubs of the toggles meet. The barrel is then expanded as faras it can go. A key is now driven through the sea-t in the hub of theplateI and through the shaftA, whereby the whole is securely locked. Thenut M is then removed, and the workman proceeds to form his core atonce, straw rope not being required, as is now the case. Vhen the coreis dry it is ready to be placed in the mold.

The bowl-piece K and the base-plate L form the head of the pipe, and theflask forming the outside of the pipe is placed around them. The core isthen lowered to its place, and, by means of the plate I fitting in theangular seat in the bowl K, it takes its proper position.

Everythin g bein g in order, the molten metal pipe plenty of room tocontract and cool withy out danger of its cracking.

This mode of working saves a large amount of labor and expense.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is-

1. A core-barrel formed of a series of segmental plates, G G, cast withthe interior inclined seats H H in one piece, and provided with V-shapedopenings cut the entire length between said plates, substantially as andfor the purposes herein set forth.

2. In combination with the segmental plates G G and their seats H H, thecentral shaft A with plates B B, hubs G D, toggles E E, and lugs d d,all constructed and arranged substantially as and for the purposesherein set forth.

3. In combination with the central shaft A, plates G G, and intermediatedevices, the bottom plate I, nut M, bowl K, and bed'plate L, allsubstantially as and for the purposes herein set forth.

4. The slotted hubs C, attached to the central shaft A by pins b passingthrough the slots in the hubs, as and for the purposes herein set forth.

In testimony that I claim the foregoing I have hereunto set my hand this19th day of' May, 1873.

WM. SMITH. Witnesses:

JOHN B. GEYsER, RICHARD ALLEN.

